Hi - I have some of these sitting about for control horns (LINK) - Are they OK and strong enough?

Thanks

Originally Posted by Jeff Watt

While that would be fun to watch (if you try it please film it ), you don't need to make this plane so complicated. Just know that if you hand toss you need throttle + good technique (or a cliff ) and you always need to REALLY pay attention. I also agree that the sandpaper in the fingerholes makes it MUCH safer. Remember to follow through!

If you try the JATO, how would you keep the exhaust from making you do the chicken dance?

Originally Posted by xviper

Put it on the ground, stand back about 50 feet before lighting it up. Someone at my flying field was also talking about attaching solid rocket pods onto one of his bigger planes. You better time the burn just right or you'll auger it into the ground.

According to eCalc my drive train which is 2 4S Turnigy 6ah powering a Scorpion 3020-890kv engine turning a Aeronaut 10x6 folder produces 2294g of static thrust. That should be enough for the X8 with standard FPV gear and an APM board along with the JATO battery ignition system, correct?

@Jeff Watt As Xviper said above I want it to be a stationary ground launch system. Something like this:

Jet Assisted Take Off (JATO) RC Plane (1 min 7 sec)

I was examining the fuselage this morning and I think it should be possible. I'll glue on a very light small aluminum sheet to mount the model rockets on. The logical place IMO is from the rear of the c/g line back. That way I'll still have the front finger holes if I did want to hand launch it for any reason. I'll have to design the mounting and release system to avoid as much drag as possible while in flight. But I figure it will basically be three cardboard standard model rocket engine mounts that will be attached to the aluminum by some sort of quick release system that will allow me to drop the tubes. Some of you might ask why I would want to do it this way? Why not? lol. I love to experiment and TRUST ME I won't be trying strapping any rockets on to my beautiful X8 without doing extensive testing. Whether the project is successful or a complete failure, it will be interesting to see.

MysticFlight,

Dude! If you can get the X8 to do that I would forever bow to you as the "Launch God"!!!

Whether the project is successful or a complete failure, it will be interesting to see.

And the understatement of the year award goes to..............

Originally Posted by TooSLow2Care

Jeff,
I run the RVOSD5 & I use a knockoff hawk sky to test the RTH & make sure I know what I'm doing during programming.

Just stuff the OSD into a cheap bird, tune it, fly out a little ways and flip the RTH switch... & hope.

That way WHEN you dork the cheap plane, you haven't ruined your X8!!

Cheers,
Brian

I've tested the RTH in the X8, and it works. However I'm still reluctant to depend on it unless I absolutely have to. I'll feel better with the Dragonlink installed. Then I'll see what distance i can get with the tracker/crosshair/ helical diversity setup. I only could hope for 3 or 4k and I'd be thrilled.

The built up sailplane in that video weighs about 1/3rd what the X8 does, and it's naturally stable,
and almost impossible to tip stall. Those rockets are launching it straight into a deep stall
from which it just pitches over and flies away. Do that with the X8 and it'll just drop a tip
and and spiral immediately to the ground. If your idea of "interesting" is a lot of smoke
and an almost immediate crash, then go for it.

ian

Originally Posted by Daemon

The built up sailplane in that video weighs about 1/3rd what the X8 does, and it's naturally stable,
and almost impossible to tip stall. Those rockets are launching it straight into a deep stall
from which it just pitches over and flies away. Do that with the X8 and it'll just drop a tip
and and spiral immediately to the ground. If your idea of "interesting" is a lot of smoke
and an almost immediate crash, then go for it.

ian

Daemon, Not that I want to doubt your aeronautical engineering experience, but have some faith man! I think it's possible! Like you said the X8 weighs wayyy more then that little sailplane. Therefore the rockets that I attach will only lift the X8 maybe a couple feet (not almost straight up and 30ft in the air like the sailplane) off the ground tops, at which point I will engage the engine. I figure 2 B motors at a 20 degree angle will do the trick.

[edit]Nevermind. Go do it. Report back when it's done.

Originally Posted by MysticFlight

According to eCalc my drive train which is 2 4S Turnigy 6ah powering a Scorpion 3020-890kv engine turning a Aeronaut 10x6 folder produces 2294g of static thrust. That should be enough for the X8 with standard FPV gear and an APM board along with the JATO battery ignition system, correct?

@Jeff Watt As Xviper said above I want it to be a stationary ground launch system. Something like this:
https://www.youtube.com/watch?v=uIcAXrHRY7M
I was examining the fuselage this morning and I think it should be possible. I'll glue on a very light small aluminum sheet to mount the model rockets on. The logical place IMO is from the rear of the c/g line back. That way I'll still have the front finger holes if I did want to hand launch it for any reason. I'll have to design the mounting and release system to avoid as much drag as possible while in flight. But I figure it will basically be three cardboard standard model rocket engine mounts that will be attached to the aluminum by some sort of quick release system that will allow me to drop the tubes. Some of you might ask why I would want to do it this way? Why not? lol. I love to experiment and TRUST ME I won't be trying strapping any rockets on to my beautiful X8 without doing extensive testing. Whether the project is successful or a complete failure, it will be interesting to see.

So you going to burn rockets every time you launch...? Seems like added expense to me, for not a huge gain - But, good luck, and videos please

Originally Posted by TooSLow2Care

Ffinybryn,
Think more about wattage than prop motor. You look at 100w-150w per Lb and you'll have nearly unlimited flight capabilities (at the 150w/lb mark)...

...you will get a lot of satisfaction of possessing this knowledge and then helping people gain the same understanding of electrical power systems.

Cheers,
Brian

Thanks for your patience Brian. I am trying to get my head around this. The BEVRC suggested motor is:
"2820/730kv. if you want to use 3s to fly x8, we recommand you choose the Nylon 13.5*7 foldering props or carbon 13*6 foldering props)"
http://www.bevrc.com/skywalker-x8-power-combo_p343.html

I have ordered a separate 80A ESC.

According to propCalc, the plane will stall with 12x8.5 and motor current exceeded using 16x10 (also poor efficiency). Only viable prop is 11x7 (with max flying time).

I have attached the eCalc's. (Closest motor is 760kv). Am I missing something?

12x8.5 only stalls a little when trying to reach max static thrust (not moving). Works fine in the air.
The 730kv motor they're recommending is for a 4S setup. They're basically guessing at a
a prop choice for that motor on 3S.

ian

Scorpion SII-3020-1110 V2 is what your using right ?

Some further progress towards maiden launch. This is MK1 and was meant to be light weight. It is but it is over complicated I now feel. Anyway this test vid has a piece of aluminium where the wings would slide into. Upon that I have taped 2 lead dive weights, this totals a bit over 3kgs. The cradle is designed to launch with the power on so I figure my 4.5Kgs X8 will exit without too much drop. As it is this test weight 'flew' 5m...flew quite well actually! I have 6x 800mm x8mm blue bungee extended approx 5-6 time their length(max).The release mech is a gate latch. to pull the cradle up I have a sprung cable underneath...no solid stopper at the end. Click for the video It has been slowed down 4x.

I use the same motor on 4s with a 10x6 Aeronaught folder....mostly because I took it from my Skywalker. It's served me very well to date and the smaller diameter give that little bit more clearance of flesh on launch.

Originally Posted by Daemon

12x8.5 only stalls a little when trying to reach max static thrust (not moving). Works fine in the air.
The 730kv motor they're recommending is for a 4S setup. They're basically guessing at a
a prop choice for that motor on 3S.

ian

Thanks for your perseverance.

Congrats on 23,000 posts.

2 Imagecatcher:

did you try handlaunching your X8?
with 1 battery for the first time, then with 2 if all is ok, then load fpv camera for 3rd time...
by 4th launch you will maybe find out there is no need for this heavy machine, although it's impressive,

it's ok for some very fast planes with small props or EDF's, that don't have much static thrust, rather spin very very fast small props to gain pitch speed.
but X8 has big prop 13-14'' which spins very slow and creates great ammount of thrust.
so much that even with 10 000 Ah 4S, a gopro, + fpv link + osd + fpv cam it can still perform a roll during takeoff, so much thrust to waste.
and if your bird is a little on a heavy side, you don't have to do roll at takeof but calm and easy takeoff from hand should be possible.

http://www.youtube.com/watch?list=PL...tailpage#t=29s